The purpose of this study is to investigate the safety and tolerability of single oral rising doses of BIA 3-202 up to 800 mg (proposed doses 10 mg, 30 mg, 50 mg, 100 mg, 200 mg, 400 mg and 800 mg) in groups of 9 healthy male adult subjects, to characterise the preliminary pharmacokinetics of single rising oral doses of BIA 3-202 in healthy male adult subjects, to investigate the effects of single doses of BIA 3-202 on COMT activity in human erythrocytes and to investigate the effect of food on the pharmacokinetics of a single dose of BIA 3-202.